1. Field of the Invention
The invention relates to a device for making a hole in the ground, which device includes a drilling head with a body provided with at least one passage for rinsing fluid, means for loosening the ground which are mounted on the body, and at least two pipes, namely a first pipe for fluid under pressure which is connected to the means for loosening the ground and a second pipe for rinsing fluid which connects to the passage.
2. Description of the Related Art
A device of the above-mentioned type is described in Belgian patent no. 905 265. This device comprises two supple hoses surrounding each other. Through the middle hose and a central opening in the body, fluid under high pressure is supplied to one or more guidable, whether or not driven and/or rotating spraying heads, which are mounted on the extremity of the body and which form the means for loosening the ground. Through the annular space between the two hoses rinsing liquid under,. lower pressure but with a higher flow rate can be pumped. The rinsing liquid flows through a channel that is situated next to or around the aforementioned central opening and through openings in the side wall cf the body, exiting in the channel, sideways out of the drilling head and further, under the washing away of loosened ground through the already formed hole toward the surface of the ground.
Although this device already permits many different ways of drilling, such as for example by changing the fluids under high and low pressure, these ways are nevertheless rather limited.